Rearrange file names
More work on the VectorLMM1 and ScalarLMMnest types
Got VectorLMM1 working to the point where betahat is properly calculated.
Finished VectorLMM1
VectorLMM1 using dense matrix methods when possible.
Messing with the names a bit
An implementation of the Gauss-Newton algorithm

This is preparatory to trying out the Laplacian approximation in nonlinear mixed-effects models.
Added a NonlinearLS type and methods for it.
Notes to self
Avoid infinite loop in fit.

The extractors like obs! and exptd! were used in evaluating the objective and were themselves calling fit.  Not goo.
Clean up the model function.
lmer always produces an LMMGeneral object.

Got the updateL function working.  Now need slvU and slvUBeta and objective.
The utils.jl file is probably not needed any more.
More fiddling with the general formulation.  It is looking pretty good now.
Got the general formulation working.  Time to move this to the main branch.